Electromagnetic field will scatter when incident on boundaries separating media with different constitutive parameters. This paper demonstrates the use of a differential operator on recorded scattered waves to reveal the shape of the boundary. The method is noninvasive and is composed of three phases. First, the area of interest is illuminated and the resulting scattered electromagnetic fields are recorded. In the 2nd phase, the captured data is numerically reverse simulated in time to reconstruct the field distribution in the region of interest. Finally, the differential imaging operator is applied on the reconstructed wave field, creating an image delineating the boundary where scattered fields originated. This technique does not require the knowledge of location of the boundaries nor the nature of the discontinuity in the constitutive parameters. The proposed imaging system is scalable, whereby modification of the source signal, recorder sampling, and numerical model allows imaging objects of smaller dimensions and creation of sharper and more accurate images
